/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hdfs.protocol;

import java.io.*;

/**
 * The base class for datanode protocol headers.
 */
public class DataTransferHeader {
  private VersionAndOpcode versionAndOp;

  protected DataTransferHeader(final VersionAndOpcode versionAndOp) {
    this.versionAndOp = versionAndOp;
  }

  protected DataTransferHeader(final int dataTransferVersion, final byte opCode) {
    versionAndOp = new VersionAndOpcode(dataTransferVersion, opCode);
  }

  protected int getDataTransferVersion() {
    return versionAndOp.getDataTransferVersion();
  }

  public void writeVersionAndOpCode(DataOutput out) throws IOException {
    versionAndOp.write(out);
  }

}
